Question

roundup, an herbicide manufactured by monsanto, has the formula C3H8NO5P. How many moles of molecules are there in a 304.3 g sample of Roundup?

Answer 1

First you find the molar mass of the formula. 

3C: 36.03g + 8H:8.08g + N: 14.01g + 5O: 80g + P: 30.97g = 169.09g

Then do the mole ratio (304.3g)x(1mole/169.09g) = 1.800 moles